Various catheters are known that differ with regard to their shape and size. For example, catheters can exhibit various diameters and lengths. Further, an opening for dispensing a liquid can be located at a distal end of the catheter or along the catheter.
For directly treating a diseased area of the body such as, for example, brain tumors or neurodegenerative diseases, it is advantageous if medicines or therapeutic agents can be directly supplied to the diseased area in the body. In order to supply a medicine to a diseased tissue, a catheter is introduced into the body, such that a catheter opening is in or near the diseased tissue or area to be treated.
However, using paediatric ventricle catheters such as hitherto have been used for treating such diseased tissue, it is not possible to dispense a particular amount of a substance safely and/or reliably in a desired area of a body. This is due in part to liquid (e.g., the substance) exiting the catheter opening and initially flowing substantially back along the surface portion of the catheter that has penetrated the tissue matrix. Thus, the liquid flows back along the catheter trajectory, away from the area to be treated. This reverse flow phenomenon is called “backflow”, wherein a reverse flow length L is proportional to the fifth root of Q×r4, where Q is the flow rate of the substance exiting the catheter and r is the outer radius of the catheter. If a sufficient supply of a substance to be administered is to be ensured, this reverse flow or backflow length L limits the ways and/or restricts the locations at which a catheter can be used or inserted. If, for example, an intracranial surface such as a sulcus is penetrated by the catheter used for an infusion or injection, it is highly probable that the back flowing fluid will disperse along the surface of the sulcus and will not reach the desired target (e.g., in front of the catheter tip). A substance exiting an opening of the catheter will only flow into the intercellular space of the tissue to be treated once the pressure exerted by the tissue on the ascending liquid adjacent to the outer side of the catheter is greater than the pressure or resistance of the intercellular space of the tissue in front of the exit opening of the catheter.